Science

A photo of a Blackburnian warbler, made ready for processing by Merlin Bird Photo ID

Users start by uploading a photo that they snapped of the bird in question, drawing a box around the animal to help the software find it, and then clicking on its bill, eye and tail to establish its orientation. They also indicate where and when they saw it.

Merlin Bird Photo ID then uses its artificial intelligence to compare data points in the photo with those from tens of thousands of photos of known species of birds – its database currently includes 400 species that are commonly seen in the US and Canada. It also takes into account the time of year and geographical location at which the photo was taken.

Within a few seconds, the software subsequently presents the user with a short list of the closest matches, including photos and song recordings.

“Computers can process images much more efficiently than humans,” says Cornell’s Prof. Serge Belongie. “They can organize, index, and match vast constellations of visual information such as the colors of the feathers and shapes of the bill.”

The program currently manages to include the correct species within the top three results about 90 percent of the time, although its accuracy should improve with increased use. That’s because it utilizes machine learning, so it builds upon the knowledge it gains each time it processes a new photo.

Plans call for the technology to be added to the existing free Merlin Bird ID app, once it’s able to reliably identify birds in photos taken with smartphones. In the meantime, you can try it out at the project website.

References:http://www.gizmag.com/

Coating condenser tubes in graphene (right) significantly improves efficiency over existing methods (left)

The brain waves that result in response to certain words could be used to verify a person’s identity

Passwords are the bane of many a computer user’s existence. Experts recommend long strings of characters containing a mix of upper and lowercase letters, numbers and symbols that may be difficult to crack, but can also be difficult to remember. Despite there being simple techniques for creating difficult-to-crack passwords that are easy to remember and horror stories of identify theft abound, the top two most common passwords remain “12345” and “password”. But a study out of Binghampton University (BU) in New York suggests brainwaves could be a promising alternative to verify a user’s identity.

Researchers at BU read a list of 75 acronyms, such as FBI and DVD, to 45 volunteers and observed the brainwaves that resulted from each group of letters, focusing on the part of the brain associated with reading and recognizing words. This was done with the placement of just three electrodes on the scalp, which is the minimum number that can be used and still obtain a clean reading.

While each respondent’s brainwaves exhibited identifiable features that were consistent in response to a given acronym, the reactions – or “brainprints” – were different enough between respondents to allow a computer system to identify each volunteer with an accuracy of 94 percent. These results were also stable over time, with identification possible after a lag of up to six months.

Sarah Laszlo, assistant professor of psychology and linguistics at BU and study co-author, says that brain biometrics offer a number of advantages over other physical characteristics used for biometrics, such as fingerprints or retinas. For example, both of these can be stolen by malicious means, rendering them unusable by the user since they can’t be replaced.

“If someone’s fingerprint is stolen, that person can’t just grow a new finger to replace the compromised fingerprint – the fingerprint for that person is compromised forever,” points out Laszlo. “Fingerprints are ‘non-cancellable.’ Brainprints, on the other hand, are potentially cancellable. So, in the unlikely event that attackers were actually able to steal a brainprint from an authorized user, the authorized user could then ‘reset’ their brainprint.”

While the researchers don’t see brainprints as a potential replacement for passwords for low security applications in the near future – after all, who wants to hook themselves up to an electroencephalograph (EEG) just to log into their email – they do see the technology having potential in high security environments.

“We tend to see the applications of this system as being more along the lines of high-security physical locations, like the Pentagon or Air Force Labs, where there aren’t that many users that are authorized to enter, and those users don’t need to constantly be authorizing the way that a consumer might need to authorize into their phone or computer,” says Zhanpeng Jin, assistant professor at Binghamton University’s departments of Electrical and Computer Engineering, and Biomedical Engineering.

The team’s study appears in the journal Neurocomputing.

References:http://www.gizmag.com/

The decellularized rat forelimb is injected with muscle and vascular cells

Currently, recipients of arm or leg transplants need to take immunosuppressive drugs for the rest of their lives, in order to keep the donated parts from being rejected. If we could grow our own replacement limbs, however, that wouldn’t be necessary. And while we do already possess the progenitor cells needed to grow such parts, what’s been lacking is a method of assembling them into the form of the desired limb. Now, however, scientists have created a shortcut of sorts – they’ve stripped the cells from one rat’s forelimb and replaced them with live cells from another rat, creating a functioning limb that the second rat’s immune system won’t reject.

Led by Dr. Harald Ott, a team at the Massachusetts General Hospital started by perfusing the donor limb with a detergent that stripped away all of its living cells. After the cellular debris was removed, all that remained was the empty non-living extracellular matrix that formerly contained the cells.

As this task was in process, progenitor cells from the recipient rat were being being grown in culture to produce muscle and vascular cells.

Once the limb was stripped of its original cells, it was placed in a nutrient solution-filled bioreactor and injected with the lab-grown cells – the muscle cells went into the individual muscle sheath sections of the matrix, while the vascular cells went into the main artery. After five days of being in the reactor, electric stimulation was applied to help the muscles grow. Two weeks later, upon being removed from the reactor, the limb was found to have functioning muscle cells in the muscle fibers and live vascular cells in the blood vessel walls.

When the muscles were activated using electrical stimulation, they were found to have 80 percent the strength of a newborn rat’s forelimb muscles. Additionally, when the limb was transplanted onto the recipient rat, its blood vessels soon filled with blood and became part of the circulatory system.

Ott and his team are now looking at ways of regrowing other limb tissues such as bone, cartilage and connective tissue. The regrowth of nerves should hopefully happen on its own. “In clinical limb transplantation, nerves do grow back into the graft, enabling both motion and sensation, and we have learned that this process is largely guided by the nerve matrix within the graft,” he says. “We hope in future work to show that the same will apply to bioartificial grafts.”

The decellularization technique utilized by the Massachusetts scientists, incidentally, has previously been used to create transplantable mouse hearts and rat kidneys. However, this is the first time that it’s been used for something more complex than an organ. The scientists have also decellularized a baboon forearm, indicating that the procedure could work on primates.

References:http://www.gizmag.com/